Folding chair with movable backrest-supporting tubes

ABSTRACT

A folding chair includes two rear legs having a predetermined shortened length and could therefore be collapsed into a rectangular body having a reduced overall length to occupy an even small space. A backrest is supported on two supporting tubes, which have lower insertion sections for inserting into upper bores of the rear legs. Push buttons are mounted in the supporting tubes and are normally pushed outward by elastic elements to engage with holes provided on the supporting tubes and the rear legs and thereby hold them together. When the push buttons are pushed radially inward, the supporting tubes could be detached from or retracted into the rear legs for the folding chair to have an even reduced collapse volume.

BACKGROUND OF THE INVENTION

[0001] The present invention relates to a folding chair, and more particularly to a folding chair having backrest-supporting tubes movably connected to upper ends of two shortened rear legs to enable further reduced collapse volume of the folding chair.

[0002] There are various chairs showing different shapes and structures to meet different functional requirements. Conventional chairs are of fixed type and occupy a considerably large space that causes inconveniences to manufacturers in packing and transporting the produced chairs. Folding chairs of different structures are therefore developed for use indoors and outdoors. Advantages of the folding chairs include reduced collapse volume for easy storage, increased number of chairs that could be delivered in one shipment at reduced freight, etc.

[0003] One of the conventional folding chairs is a folding chair having canvas seat and backrest. When the folding chair is not in use, its rear legs and a plurality of sets of articulated tubes partly serving as front legs could be collapsed into a generally rectangular body that is convenient for carrying and could be extended for use at anytime. This type of folding chair usually includes two rear legs having upper portions projected from the seat by a considerably large distance to support the canvas backrest between them. The long rear legs project from an end of the rectangular body of the collapsed folding chair and therefore increase an overall length and volume of the collapsed chair, resulting in increased freight cost. It is therefore desirable to improve the conventional folding chairs having such long rear legs.

SUMMARY OF THE INVENTION

[0004] A primary object of the present invention is to provide a folding chair having movable backrest-supporting tubes, so that the backrest-supporting tubes may be detached from or telescopically retracted into two hollow rear legs of the chair when the chair is collapsed, enabling the folding chair to have an even reduced collapse volume.

[0005] To achieve the above and other objects, the folding chair of the present invention mainly includes two rear legs having a predetermined shortened length and could therefore be collapsed into a rectangular body having a reduced overall length to occupy an even smaller space. A backrest is supported on two supporting tubes, which have lower insertion sections for inserting into upper bores of two rear legs. Push buttons are mounted in the supporting tubes and are normally pushed outward by elastic elements to engage with holes provided on the supporting tubes and the rear legs and thereby hold them together in an extended state for use. When the push buttons are pushed radially inward, the supporting tubes could be detached from or retracted into the rear legs for the folding chair to have an even reduced collapse volume.

BRIEF DESCRIPTION OF THE DRAWINGS

[0006] The structure and the technical means adopted by the present invention to achieve the above and other objects can be best understood by referring to the following detailed description of the preferred embodiments and the accompanying drawings, wherein

[0007]FIG. 1 is a front perspective view of a folding chair according to a first embodiment of the present invention;

[0008]FIG. 2 shows a backrest of the folding chair of FIG. 1 is detached from rear legs of the chair;

[0009]FIG. 3 is a fragmentary, enlarged view of FIG. 2;

[0010]FIG. 4 is an enlarged sectional view of the encircled area A of FIG. 1;

[0011]FIG. 5 is a perspective view showing the folding chair of FIG. 1 in a first folded state;

[0012]FIG. 6 is a perspective view showing the folding chair of FIG. 1 in a second folded state;

[0013]FIG. 7 is a rear perspective view of a folding chair according to a second embodiment of the present invention, wherein the backrest is detached from two supporting tubes thereof;

[0014]FIG. 8 is a fragmentary, exploded perspective view showing the structural relation between the rear leg and the backrest-supporting tube of the folding chair of FIG. 7; and

[0015]FIG. 9 is an enlarged and assembled vertical sectional view of FIG. 8.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] Please refer to FIG. 1 that is a front perspective view of a folding chair having canvas seat 30 and backrest 50 according to a first embodiment of the present invention. This type of canvas folding chair typically includes two spaced rear legs 10, 20 being connected to each other with a first set of intersected and articulated tubes 11, 12. A second and a third set of intersected and articulated tubes 13, 14 and 15, 16, respectively, are separately connected to the two rear legs 10, 20 to locate in front of them, and a fourth set of intersected and articulated tubes 17, 18 is connected to the second and the third set of articulated tubes 13, 14 and 15, 16 to locate in front of them. The rear legs 10, 20 and the articulated tubes 11 to 18 are essentially made of hollow metal tubes.

[0017] The canvas seat 30 has dimensions decided according to a length of the articulated tubes 11 to 18, so as to locate at a predetermined height relative to the rearlegs 10, 20. To facilitate easy manufacturing and assembling of the whole folding chair, a plurality of shape-identical connectors 40 are separately provided at four lower corners of the canvas seat 30 and four bottom corners of the folding chair to pivotally join the rear legs 10, 20 and the articulated tubes 11 to 18 at these connectors 40.

[0018] With the above arrangements, the folding chair could be folded into a substantially rectangular body to occupy a largely reduced space. In a conventional folding chair having similar structure, the two rear legs 10, 20 have upper portions that are upward extended by a certain distance to support the canvas backrest 50. These upward extended portions of the rear legs 10, 20 project from an end of the rectangular body of the folded chair, making the folded chair have an increased overall length and volume.

[0019] To solve this problem, the folding chair according to the first embodiment of the present invention, as shown in FIGS. 2 to 4, includes two shortened rear legs 10, 20 and two supporting tubes 60, 70 for the canvas backrest 50 detachably connected to upper ends of the two rear legs 10, 20. The supporting tubes 60, 70 are formed at their lower portions with diameter-reduced insertion sections 61 and 71, respectively, for fitly inserting into inner bores 101, 201 at the upper ends of the hollow rear legs 10, 20. Elastic elements 62 and 72 are mounted in the hollow insertion sections 61 and 71, respectively, at predetermined height relative to the rear legs 10, 20, respectively. In a preferred embodiment of the present invention, as shown in FIG. 3, the elastic elements 62, 72 include a coiled main body having two extended arms 63, 64 and 73, 74 spaced from one another similar to a letter V. One of the two extended arms 63 or 64, 73 or 74 of both elastic elements 62, 72 has a push button 65, 75 pre-connected thereto.

[0020] The elastic elements 62, 72 are mounted in the supporting tubes 60, 70 to normally elastically project the push buttons 65, 75 from first radial through holes 66, 76, respectively, provided on the diameter-reduced insertion sections 61, 71. Meanwhile, the two rear legs 10, 20 are provided near upper ends thereof with second radial through holes 102, 202, respectively. When the supporting tubes 60, 70 along with the canvas backrest 50 are connected to the rear legs 10, 20 by inserting the diameter-reduced insertion sections 61, 71 into the hollow bores 101, 201 of the rear legs 10, 20, respectively, the projected push buttons 65, 75 are initially pushed radially inward by the upper ends of the rear legs 10, 20, and then radially spring outward to locate in the second radial through holes 102, 202 when the push buttons 65, 75 reach at the through holes 102, 202, respectively, as shown in FIG. 4. To detach the supporting tubes 60, 70 from the rear legs 10, 20, simply push the push buttons 65, 75 in a direction indicated by the arrow in FIG. 4 to disengage the push buttons 65, 75 from the second radial through holes 102, 202, allowing the backrest 50 and the supporting tubes 60, 70 to separate from the folding chair.

[0021] After the backrest 50 is detached from the rear legs 10, 20, the folding chair of the present invention as shown in FIG. 1 could be folded into a rectangular body, as shown in FIG. 5. The detached backrest 50 and supporting tubes 60, 70 are received in the canvas seat 30 that is now folded and enclosed in the collapsed four sets of articulated tubes 11 to 18, and do not occupy any additional space. Alternatively, in a more preferable embodiment of the present invention, the backrest 50 is provided at two ends with fastening means, such as hook tape and loop tape of a Velcro tape, for binding around the folded rectangular body of the folding chair, as shown in FIG. 6.

[0022] FIGS. 7 to 9 illustrates a folding chair according to a second embodiment of the present invention. In the second embodiment, the folding chair includes two rear legs 100, 200; and two supporting tubes 600, 700 for supporting a backrest 500. The folding chair of the second embodiment is generally similar to the folding chair of the first embodiment, except that the two supporting tubes 600, 700 are normally telescopically received in hollow upper portions of the two rear legs 100, 200, respectively.

[0023] In a most preferable form of the second embodiment of the present invention, the supporting tube 600, which is identical to the supporting tube 700 and is therefore described alone hereinafter, has a pair of upper and lower elastic elements 620, 620A mounted therein. Please refer to FIG. 8. Two push buttons 650, 650A are respectively connected to an extended arm of the elastic elements 620, 620A, so that the push buttons 650, 650A are oriented to two opposite directions and normally engaged with a first pair of radial through holes 670 provided near a lower portion of the supporting tube 600. The supporting tube 600 and a corresponding one 100 of the two rear legs 100, 200 are correspondingly formed at predetermined positions on their tube walls by means of, for example, stamping, with two axially extended recesses 690 and 190, respectively, that serve as guide rails for the supporting tube 600 to telescope in the rear leg 100 and slide up and down in a track defined by the engaged recesses 690 and 190.

[0024] With the recesses 690, 190, the supporting tube 600 is adapted to normally couple with the rear leg 100 when the push buttons 650, 650A are elastically pushed radially outward by the elastic elements 620, 620A to engage with and project from a second pair of radial through holes 170 provided near an upper end of the rear leg 100 (see FIGS. 7 and 9). And, when the two push buttons 650, 650A are radially pushed inward to disengage from the second pair of radial through holes 170, the supporting tube 600 could be downward pushed into the hollow rear leg 100.

[0025] The supporting tubes 600, 700 are provided at their respective tops with diameter-expanded heads 680, 780 to serve as stoppers that prevent the supporting tubes 600, 700 from fully retracting into the hollow rear legs 100, 200.

[0026] To collapse the folding chair, a user needs only to apply a force to downward push the supporting tubes 600, 700 into the hollow rear legs 100, 200. And, to extend the folding chair, the user may grip at the expanded heads 680, 780 to pull the supporting tubes 600, 700 out of the rear legs 100, 200. When the supporting tubes 600, 700 have been pulled for the push buttons 650, 650A of the elastic elements 620, 620A to reach at the second pair of radial through holes 170 on the rear legs 100, 200, the push buttons 650, 650A automatically spring out to engage with the holes 170 and locate the supporting tubes 600, 700 in place relative to the rear legs 100, 200. The canvas backrest 500 could then be put over the upward extended supporting tubes 600, 700.

[0027] With the detachable or the retractable backrest supporting tubes, the folding chair could be collapsed into an even smaller volume, which enables the manufacturer to economically pack and transport the finished product of folding chair having a reduced collapse volume. The number of folded chairs that could be delivered in each shipment could therefore be largely increased to create additional profits.

[0028] The present invention has been described with some preferred embodiments thereof and it is understood that many changes and modifications in the described embodiments can be carried out without departing from the scope and the spirit of the invention that is intended to be limited only by the appended claims. 

What is claimed is:
 1. A folding chair with movable backrest-supporting tubes, comprising two spaced hollow rear legs having a predetermined shortened length and being connected to each other by means of a first set of intersected and articulated tubes; a seat; a second, a third, and a fourth set of intersected and articulated tubes connected to two lateral sides and a front side of said seat, respectively; and a plurality of connectors provided at four upper and four lower corners of said folding chair to pivotally join said rear legs, said seat, and said four sets of intersected and articulated tubes, such that said folding chair could be collapsed into a rectangular body; said folding chair being characterized in that a backrest thereof is supported on two separate supporting tubes, each of which including a preformed insertion section having at least one elastic element mounted therein to normally elastically project a push button from a wall of said supporting tube, that said supporting tubes are adapted to downward insert into upper inner bores of said shortened hollow rear legs and to stably locate in said rear legs when said push buttons on said two supporting tubes reach at and separately engage with two radial through holes provided near upper ends of said two rear legs, and that said supporting tubes are adapted to separate from said rear legs by pushing said push buttons radially inward to disengage from said rear legs and pulling said supporting tubes from said rear legs.
 2. The folding chair with movable backrest-supporting tubes as claimed in claim 1, wherein said at least elastic element for each of said supporting tube includes a coiled main body having two extended arms in the form of a letter V, and said push button being connected to one of said two extended arms to be normally pushed outward to elastically engage with a radial through hole provided on a wall of said insertion section of said supporting tube.
 3. The folding chair with movable backrest-supporting tubes as claimed in claim 1, wherein said insertion section of each said supporting tube has reduced diameter for fitly inserting into a corresponding one of said two rear legs.
 4. The folding chair with movable backrest-supporting tubes as claimed in claim 1, wherein said insertion sections are integrally extended from said supporting tubes, and each of said supporting tubes being formed with a first axial recess corresponding to a second axial recess provided on each of said rear legs, so that said first and said second axial recesses engage with each other to define a track for said supporting tube to telescopically slide in said rear leg; and wherein said supporting tubes are provided at upper ends with diameter-expanded heads as stoppers to prevent said supporting tubes from being fully inserted into said rear legs.
 5. The folding chair with movable backrest-supporting tubes as claimed in claim 4, wherein each of said supporting tubes has a pair of said elastic elements mounted therein to orient toward two opposite directions.
 6. The folding chair with movable backrest-supporting tubes as claimed in claim 5, wherein said backrest is pre-connected to and normally supported on said two supporting tubes. 